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AdBlue is a solution of urea in demineralised water (32,5%) used as an operating fluid in diesel-powered freight trucks to improve emissions. It is a common misconception that AdBlue is a fuel additive. AdBlue has a separate tank to the fuel and is sprayed into the exhaust gases. Therefore, it is never mixed or added to the fuel.

AdBlue is taken along in a separate tank on the freight trucks. It is dosed in the hot exhaust gases in a specific catalytic converter. The oxides of nitrogen formed at combustion are converted into elementary nitrogen and water. This method is called Selective Catalytic Reduction (SCR).

The usage of AdBlue lies at 3 to 5% of the diesel usage. Because of this it becomes possible for diesel-powered freight trucks to satisfy the Euro IV emission standard introduced in 2005, as well as the future Euro V emission standard. Because there are already many of these so called "EURO V - trucks" or "SCR - trucks" on the road, filling stations that supply AdBlue are being built, expanding an infrastructure that makes use of urea in emission control feasible.

In order to ensure that the SCR (Selective Catalytic Reduction) remains free from contaminant, correct materials of construction must be used for both storage and dispensing. Manufacturers of the SCR have specified that without using compatible materials of construction ions can be passed from the dispensing materials and into the porous head on the SCR. This can render the SCR ineffective and reduce it’s life expectancy from +500000 km to less than 200000 km. Equipment which may prove suitable for Urea solution is often not compatible with AdBlue and this common assumption has led to a number of systems failing prematurely.

To ensure that the AdBlue is not affected by incorrect material specification operators should refer to the DIN70070 standard for production of AdBlue and CEFIC quality control document AUS32.

Leading industry players have sponsored a website called, which includes a search engine that can be used to find filling stations that offer AdBlue, and which has maps showing their location.

External links

Producers of AdBlue:

Suppliers of AdBlue:

Suppliers of AdBlue Dispensing Equipment:

Euro IV comes into force in October 2006 Euro V comes into force in October 2008